Automated system and method for subscriber line service control

ABSTRACT

A signal band width limiter is provided in a telecommunication path that includes a leased unbundled subscriber line. The limiter may be a programmable active filter such as a digital signal processor in which filter characteristics are set under control of a controller at a central office. The controller may acquire the necessary subscriber level information via a data network from a data base at a remote location. Band pass ranges are set to frequencies corresponding to subscribed services. As the subscribed service is changed, replacement by the appropriate passband filter readily can be made. The telecommunication path can be monitored to determine whether an upgrade of service is required. Parameters of subscriber line leased from an ILEC by a CLEC can be tested at the ILEC premises.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/138,407filed on Aug. 24, 1998, which is a continuation-in-part application ofapplication Ser. No. 09/138,408, filed Aug. 24, 1998, now U.S. Pat. No.6,035,029.

TECHNICAL FIELD

The present invention relates to telecommunications, more particularlyto automated ILEC control of the level of service delivered over linesprovided for CLEC service providers.

BACKGROUND OF THE INVENTION

Recent legislative and regulatory changes have been made to spur a moreopen service provider environment in the telecommunications industry.Subscription to local telephone service, open to competition, no longerwill be limited to incumbent local exchange carriers (ILECs) such as theregional Bell Operating companies.

One aspect of this open environment policy pertains to competing localexchange carriers (CLECs) that are facility based, e.g., those competingcarriers that have their own independent switching facilities. Thesefacilities must be integrated into the public switched telephone network(PSTN) in a seamless manner from the user's perspective. The concept ofuser telephone number portability is basic to this end. In general,number portability refers to the ability of end users to retain theirgeographic or non-geographic telephone number when they change theirservice provider, their location, or their service. A wide applicationof number portability, for example, would permit a user to keep the sametelephone number at the same or different location, while terminatingservice from one provider in favor of a new service provider, and movingfrom plain old telephone service (POTS) to integrated digital servicesnetwork (ISDN). The Federal Communications Commission has proposedstandards for local number portability (LNP) that relates to the abilityof a telephone service subscriber to select or change the selection of acarrier for providing that customer's local telephone service, whilestill maintaining the subscriber's telephone number at the same customerpremises.

FIG. 1 is a simplified diagram exemplifying a public switched telephonenetwork in which switching facilities of both an incumbent localexchange carrier and a competing local exchange carrier are availablefor direct loop connection to the subscriber. A customer havingtelephone or like communication equipment at station 11 may obtain localexchange telephone service from either an original ILEC served by itsend office 13, or a CLEC having an end office 15. The CLEC end office 15may connect through trunk circuits to each ILEC end office in the areaof service or to a trunk connection with an access tandem 23. Althoughnot shown, the CLEC end office 15 also would connect into the commonchannel interoffice signaling network, at least for the exchange ofcall-setup related signaling messages. In the illustrated example, thesubscriber at station 11, who originally received service through theILEC has now selected the CLEC in replacement thereof for local service.Accordingly, the station 11 is shown connected to the CLEC end office15, the previous subscriber loop connection to ILEC end office 13 havingbeen disabled. Signaling Transfer Point (STP) 19 and Integrated ServiceControl Point (ISCP) are components of the known Advanced IntelligentNetwork (AIN) within which at least part of the common channelingsignaling network is included. Various approaches have been undertakento provide number portability for an arrangement such as this examplethat are not directly relevant to the present invention.

Another aspect of the open environment policy is embodied in arequirement that an ILEC unbundle certain network elements and servicesand offer use of those elements and services to other carriers, CLECswho may have remotely located switches but do not have facilities fordirect local connection, for resale to end users. The ILEC, for example,must make available for sale to another carrier an unbundled port on anend office switch. The other carrier can then become a competing localexchange carrier by reselling services of the switch to end users havinglocal loops that connect to the end office switch. The statutory andregulatory changes also require that customized routing be available forboth unbundled switching and for resale. Customized routing is the termused in the regulations for routing calls made in the ILEC switch tolocations other than normal routing locations.

Telephone service capability, of course, has extended beyond the POTSvoice and ISDN communication of decades ago. With the advent of digitalcommunications, the variety of telecommunication services and number ofspecialized service providers have increased at a remarkable pace. Theavailability of information in the form of data from various sources hasspurred large public demand for broadband data transfer that challengesthe capabilities of communication delivery systems. The number ofinformation sources publicly and interactively available via theinternet to personal computers, as well as private data network sources,continues to proliferate. Full motion video programming and sourcematerial also has rapidly progressed from early television broadcastingand cable distribution networks to a wide variety of distributionarrangements, including direct broadcast satellite television. Thenumber of full motion video sources has expanded in response toincreased usage and user demand for a greater range of subject mattercontent.

To meet user requirements, more robust broadband networks have evolved.For example, U.S. Pat. No. 5,247,347 to Litteral et al., discloses adigital video distribution network providing subscribers with access tomultiple Video On Demand service providers through the public switchedtelephone network. The subscriber may transmit ordering information viathe public switched telephone network to the independent videoinformation providers. Video programming may be accessed and transmittedto the subscriber directly from a video information provider (VIP) orthrough a video buffer located at a central office (CO) serving thesubscriber. Connectivity between the central office and the subscriberfor transmission of video data is provided by an asymmetrical digitalsubscriber line (ADSL) system. ADSL, which has been standardized by ANSIas T1.413, uses existing unshielded twisted pair copper wires from thetelephone company central office to the subscriber's premises. Equipmentat the central office and the subscriber's premises permits transfer ofmore high speed digital information signals to the subscriber than inthe reverse direction. The standard is directed to carrying video(broadband) to the home while returning control signals from the home at16 Kbps.

In the Literal et al. patent, ADSL interface units at the central officemultiplex digital video information with voice information to betransmitted to the subscriber and support two-way transmission betweenthe subscriber's line and the X.25 packet data network of one or morecontrol channels. A subscriber may use either a standard telephoneinstrument over the public switched telephone network or a dedicatedcontrol device over an ISDN packet network to order video programming.The request is transmitted to a designated video information providerand digital transmission connectivity is established between the videoinformation provider and the central office serving the subscriber.Connectivity between the central office and subscriber is provided byasymmetrical digital subscriber line interface units over a local loop.The interface units frequency multiplex digital video information withvoice information to the subscriber and support transmission of areverse transmission channel from the subscriber to the central officefor transmission on the ISDN packet data network back to the videoinformation provider. The interfaces also allow baseband signaling andaudio between the central office and the subscriber for conventionaltelephone instrument connectivity. A complimentary ADSL interface unitat the subscriber's premises separates downstream video control signalsand voice telephone signals from the line and multiplexes upstreamcontrol signals and voice telephone signals onto the line. A similarpublic switched telephone network multimedia information ADSL deliverysystem is disclosed, for example, in U.S. Pat. No. 5,528,281 to Grady etal.

ADSL offers a wide range of other applications, such as in education,health care, work-at-home access to corporate LANS and interactiveservices. HDSL has more recently evolved to provide T-1 capability on anormal twisted pair. Implementation may include various bit rates ineither direction.

U.S. Pat. No. 5,200,993, issued Apr. 6, 1993 to Wheeler et al.,describes a public telephone network distributed imaging system havingenhanced capabilities. The distributed imaging system providescentralized image processing to end users and access to a range of imagemanagement capabilities residing on a shared platform distributedthrough a switched telephone system. The shared platform functions as aservice bureau in delivering such capabilities to end users.

The distributed imaging system embodies an image platform based on theclient-server model with standard communications interfaces to servicemultiple separate user groups accessing different applications. Usergroups can supply applications programs which are stored and run on thecentral hardware in support of respective user requirements. The imageserver operations are provided as functional primitives. Userapplications are provided by combining the primitives in a controlscript.

The provision of myriad services, such as those exemplified above,places a challenge on the ILEC to appropriately correlate usage of itssubscribers with the various services offered so that dependable servicecan be provided and billing accounted therefor. With access to the finallink to the subscriber available to CLECs, this challenge is furthercomplicated. An end user may subscribe to various services through aCLEC of its choice, while provision of these subscribed services isconveyed through the plant of an ILEC. The ILEC must be able todetermine whether the usage comports with its available capabilities andbe able to apply the appropriate billing rates to usage that exceed thestandard POTS charges. To further complicate this functionality,services may be distributed among several LECs. For example, the ILECmay continue to provide POTS service to a particular subscriber, whiledata services may be obtained from a different provider.

Commonly assigned co-pending application Ser. Nos. 08/598, 768 and08/598,772 to Montgomery et. al., both filed Feb. 9, 1996, are directedto utilizing portions of the existing public switched telephone networkfor alternate purposes, while efficiently and conveniently providing amethod of measuring the usage of such circuits for billing purposes. Oneor more telephone company local loops to subscriber premises may beutilized in whole or in part for providing to such premises a connectionto the service platform of a third party alternate service provider. Thealternate service provider may be another local telephone company, aninterexchange carrier, a video service provider, a multi-media serviceprovider, or the like. The use of the local loop is leased to the thirdparty service provider at a rate dependent upon the usage and nature ofusage of the circuit. Information and data to permit efficient andconvenient billing for leased usage of such loops is implemented byproviding on the local loop a passive monitor. The monitor detects andtemporarily stores data relating to the commencement and termination ofsignaling, the time of day, and the nature of the signaling that occurs.Thus, charges may be dependent not only upon the time duration ofsignaling, but also on the rate of information transferred. Datacollected from the monitors is stored at a monitor center from which itis transferred to a billing operation such as the telephone companyRevenue Accounting Office (RAO). The arrangements of these applicationsare reactive in nature, from the standpoint that communication activityis observed and accounted for so that appropriate billing and any otheraccounting functionalities can be accurately provided.

The need remains for the ability, proactively, to determine thatappropriate service will be provided to subscribers. In the currenttelephone system it is difficult to determine what kind of transmissionis occurring on a particular pair of wires at any given time withoutphysically accessing the wires and measuring activity. With the currentsystem, the ILEC, who unbundles transmission pairs to be used by CLECcustomers, cannot realistically sell to the CLEC separate classes ofservice and be assured that a subscriber to POTS will receive only POTSservice and not a higher rated service, for example, ADSL. As ADSLcontinues to evolve, higher data rates have become available indifferent classes of ADSL service offerings. Usage higher than that forwhich the line is subscribed not only would cost the ILEC the differencein billing for over the subscribed class of service, but also may exceedthe planned transmission capacities of the ILEC plant.

A related problem exists if an unbundled line is leased to a dataservices provider for use only for data communication, such as ADSL. Theend user would retain POTS service subscription from the ILEC throughthe separate original line in addition to the newly acquired dataservice through the leased line. The ILEC should be able to maintaincontrol over the leased line to limit use to the subscribed level ofdata communication. It would be highly desirable for such control to bemaintained on an automated basis with a minimum of human interaction.

SUMMARY OF THE INVENTION

The present invention overcomes the aforementioned problems. Anadvantage of the present invention is that a LEC provider canautomatically limit service of a POTS subscriber to POTS only,regardless of whether the subscriber terminating link is provided by adifferent local exchange carrier.

An additional advantage of the present invention is that an ILECprovider can proactively limit the communication services offered overunbundled lines leased to CLECs to within prescribed signal frequencytransmissions.

A further advantage of the present invention is that changes in thelimitations placed on leased unbundled lines can readily be made asservice offerings change. Provisioning such changes can be made in anautomated fashion with a minimum of human intervention.

These and other advantages are satisfied, at least in part, by theprovision of a signal band width limiter in the communication path thatincludes the leased unbundled subscriber line. The signal limiter may bea low pass frequency filter having a band pass range set to thefrequencies corresponding to the subscribed services. Thus, if only POTSservice is offered, the filter has a passband range for passing onlytelephone service signals in a POTS analog frequency range. For ISDNservice, the filter has a passband range for passing only telephoneservice signals within a frequency range prescribed for ISDN. For higherspeed data services, such as HDSL and ADSL, filters with appropriatepass bands, up to complete pass through, are provided in the subscribercommunication path. As the subscribed service is changed, replacement bythe appropriate passband filter readily can be made.

The signal limiter may be located at the central office of the ILEC,such as at the main distribution frame. The CLEC may have ADSLfacilities collocated with the ILEC central office. With such anarrangement, the CLEC can provide ADSL service and POTS service over thesame loop or the CLEC, or other provider, can provide ADSL service to asubscriber over an unbundled ADSL loop while POTS service is providedthe same subscriber over a separate POTS loop. If an unbundled loop isleased solely for a particular level of data communication service whilethe original POTS line remains under subscription to the ILEC, a bandpass filter with the appropriate frequency range is inserted in theleased line communication path.

The ILEC central office may be equipped to provide fiber lines to remotelocations such as controlled environmental vaults (CEVs) from whichtwisted pair may then be run to the subscriber premises. The signallimiters can be connected to distribution frames at such remotelocations in lieu of central office main distribution frame connection.

Additional advantages of the present invention will become readilyapparent to those skilled in this art from the following detaileddescription, wherein only the preferred embodiment of the invention isshown and described, simply by way of illustration of the best modecontemplated of carrying out the invention. As will be realized, theinvention is capable of other and different embodiments, and its severaldetails are capable of modifications in various obvious respects, allwithout departing from the invention. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the attached drawings, wherein elements having thesame reference numeral designations represent like elements throughoutand wherein:

FIG. 1 is a simplified diagram exemplifying a public switched telephonenetwork in which switching facilities of both an incumbent localexchange carrier and a competing local exchange carrier are availablefor direct loop connection to the subscriber.

FIG. 2 is a simplified diagram of an embodiment of the present inventionin which a user's only subscriber line can be leased to a competingservice carrier capable of providing both POTS service and ADSL serviceover the same loop.

FIGS. 3(a)-3(c) are illustrations of plug-in band width limiters whichmay be used in the preferred embodiments of the invention.

FIG. 4 is a simplified diagram of an embodiment of the present inventionin which a customer premises is provided with two subscriber lines, oneline receiving POTS service from an incumbent LEC, the other line leasedto a competing service carrier capable of providing both POTS serviceand ADSL service over the same loop.

FIG. 5 is a simplified block diagram illustrative of an embodimentaccording to the present invention in which a CLEC leased subscriberline is connected to an incumbent LEC distribution frame located at asite remote from the central office.

FIG. 6 is a simplified block diagram of another embodiment according tothe present invention providing automated selection of appropriate bandwidth limiting characteristics for subscriber loop service control.

FIG. 7 is a simplified block diagram of an embodiment of the presentinvention similar to the arrangement of FIG. 6 but further modified toprovide monitoring and testing feedback.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 is one example of an embodiment of the present invention in whichan unbundled subscriber loop 23, serving customer premises 30, is leasedby a competing provider from the local exchange carrier. The customermay have high speed data equipment 32, such as a computer with ADSLcapability or the like, as well as standard telephony stationsdiagrammatically shown as telephone set 34. Access to the subscriber atthe customer premises may be made through a conventional networkinterface device (NID) 25. POTS splitter 36, which also may be any ofmany conventional devices, splits analog signals for POTS communicationwith set 34 from the data communication delivered to equipment 32. Thesplitter also combines analog and data signals transmitted from thesubscriber premises.

The subscriber loop is connected to distribution frame 52 of maindistribution frame 50, located at the LEC central office 40. Alsolocated at the central office are the central office switch 42 and CLECequipment 60, comprising POTS splitter and ADSL equipment 64. The ADSLequipment, shown diagrammatically in block form at customer premises 30and in the central office may comprise well known elements such asdescribed, for example, in the aforementioned Litteral et al. patent.The central office switch interconnects with the public switchedtelephone network in conventional manner. The central office containsmany other conventional elements, those which are not necessary forexplanation of the current invention being deleted from the drawing forsimplicity of illustration. CLEC equipment 60 is connected to frame 54of the main distribution frame 50, as well as to its own network 66.Network 66 may comprise, in whole or in part, elements of othercommunication networks. While shown collocated at the LEC centraloffice, equipment 60 may be located at a location remote from thecentral office 40. It is to be understood that FIG. 2 is merelyillustrative and represents, for simplicity, only one subscriber and onealternate provider of many that may be served through the LEC office.

Connected between frames 52 and 54 is band width limiter 56 in acommunication path that includes the subscriber line 23 and POTSsplitter 62. The band width limiter serves to block signals in this pathhaving frequencies outside the range that corresponds to subscribedservices. The POTS splitter combines incoming analog POTS signals anddata signals from the CLEC network that are received from differentpaths. Incoming POTS signals are received through the upper portion offrame 54. High speed data signals are received through the exemplaryADSL equipment 64. The combined signals are applied from the POTSsplitter through the lower portion of frame 54 to the band widthlimiter. Outgoing signals from the subscriber line 23 travel a paththrough the band width limiter, lower portion of frame 54 and the POTSsplitter, whereupon the signals are split for transmission of POTSsignals through the upper frame portion path and the data signalsthrough the ADSL equipment and back to the CLEC network.

The band width limiter 56 may comprise any well known filter orfrequency attenuator that limits the transmission of signals within theprescribed frequency pass band range in its simplest form, low passfilters such as RLC circuits can be used. The upper range limit of theparticular filter to be used can be fixed by an appropriate filtercircuit that correlates with the subscribed service. Filter circuitshaving various frequency pass ranges for the respective services can besupplied as plug-in units for easy installation at the main distributionframe.

Examples of such units are illustrated diagrammatically in FIGS.3(a)-3(c). The low pass filter F1 of FIG. 3 (a) will permit transmissionof signals up to approximately 10 KHz to allow for analog POTS serviceto the subscriber. Such a filter, for example, may include a load coil.The low pass filter F2 of FIG. 3(b) will permit a frequency pass rangeof up to 80 KHz, sufficient to service a digital subscriber line (DSL)such as provided for ISDN service. The low pass filter F3 of FIG. 3(c)will permit a frequency pass range up to the level required for HDSL andADSL frequencies. The limit of 400 KHz shown permits HDSL service.

In operation, upon establishing the subscribed level of service, theappropriate low pass filter unit can be plugged into the subscriber lineat the main distribution frame. Thus, if only standard POTS service hasbeen allocated to the subscriber line, filter F1 will be inserted in thecommunication path so as not to permit ADSL transmission over thesubscriber line. If a service upgrade is later desired, filter F1readily can be replaced by the appropriate plug-in F3 filter.

In the embodiment of FIG. 4, customer premises 30 is provided with twosubscriber lines, line 23 receiving POTS service from the incumbent LECvia central office 40, line 23′ leased to a CLEC capable of providingboth POTS service and ADSL service over the same loop. Each of lines 23and 23′ are assigned individual telephone numbers. Line 23 is connectedin conventional manner to the main distribution frame and to the switch42 at the central office. Line 23′ is arranged to be served in a mannersimilar to the embodiment shown in FIG. 2. The band limiter 56 maycomprise the appropriate low pass filter, as described with respect toFIG. 3, that corresponds to the service subscribed from the CLEC andleased from the incumbent LEC. If the leased service is not within theADSL standard, the appropriate band width limiter will prevent provisionof ADSL service.

Line 23′ alternatively may be leased only for data network services, theincumbent LEC exclusively providing POTS services over line 23. Toensure that services are conform to this arrangement, a frequency bandpass limiter having filter band pass characteristics that match only thesubscribed data network service(s) will be used for BWL 56. In theillustrated example, only ADSL signals will passed over the subscriberline 23′. In this example, the CLEC POTS splitter and analog loopconnection through the upper portion of frame 54 would not be providedat the central office 40.

FIG. 5 is a simplified block diagram of an embodiment of the inventionin which subscriber lines are connected to an incumbent LEC distributionframe located at a site remote 70 from the central office. As an exampleof this embodiment, the LEC end office may be equipped with fiber optictransmission capability, whereby optic fiber communication lines extendfrom the end office to a controlled environmental vault (CEV) 70 at theremote location. O/E interface converts optical transmission signalsreceived from the end office to electrical transmission signals whichare fed to time slot interchange 74. Line cards 76 separate signals tobe routed to the appropriate subscriber lines via distribution frame 52.As in the previous embodiments, subscriber line 23 is leased to a CLEC,which may have a twisted pair connection from the CLEC network todistribution frame 54 in the CEV. Band width limiter 56, connectedbetween distribution frame portions 54 and 52, is selected to providethe appropriate frequency pass band that corresponds to the subscribedservice.

FIG. 6 is a simplified block diagram illustrative of an automatedarrangement for selection of appropriate filter band widthcharacteristics for the subscribed loop service. This embodiment maycontain the same elements as the embodiments of FIGS. 2 and 4 withfurther modification and additions exemplified in the drawing figure.The leased subscriber line 23 is part of a communication path thatincludes, in the ILEC central office, distribution frame portions 52 and54 and digital signal processor 80, and connection to the CLEC network.DSP 80 is connected to, and under the control of, controller 82, thelatter including microprocessor capability or the like. Unlike thepassive filters, the digital signal processor is programmable to effectselectively from a plurality of filter band pass characteristics havingpass ranges matched to the respective services that may be leased by theLEC. The digital signal processor thus operates as an active filter thatwill attenuate signals outside of the selected frequency range. By wayof example only, a controller and attenuator such as the commerciallyavailable Counseltronics DLS 400 can be utilized. Controller 80 isconnected to a data network 84 through an appropriate data interface 86.Network 84 may comprise an ILEC private data network through whichcommunication among the various system components, such as centraloffices, data base storage 88 and control terminal 90 can occur.

In operation, the level of subscribed service is agreed upon by the userand the CLEC who leases the subscriber line from the ILEC. The ILEC willenter data descriptive of the leased service for the subscriber line, aswell as any other subscriber lines, through a terminal such as unit 90for storage via the data network 84 in a database 88. The controller 82at the central office receives the subscriber line service informationvia the data network either from the terminal 90 or the database source.In response, the controller runs the program for selection of theappropriate filter characteristics at DSP 80.

The embodiment of FIG. 7 provides monitoring and testing features in thearrangement of FIG. 6, which has been modified in the followingrespects. Connected in the subscriber communication path between frameportion 54 and DSP 80 is monitor 92, which is shown linked to controller82 by a single connection line. This line represents one or more datapaths between the two units by which control signals are sent from thecontroller to the monitor and return signals are sent from the monitorto the controller. Connected in the subscriber communication pathbetween DSP 80 and frame portion 52 is relay unit 94, which is alsoconnected to test unit 96 and controller 82. Monitor 92 may be similarto monitors more fully described in the aforementioned co-pendingapplications 08/598,768 and 08/598,772. Test unit 96 may comprisemechanized loop test equipment common to central office switchingsystems.

In operation, monitor 92 detects power distribution over the frequencyspectrum for signals received from the CLEC prior to attenuation at DSP80. Predetermined power thresholds may be set to indicate use offrequency range transmission. Identification of the frequency pass bandrange selected by the controller for the programmed DSP is sent by thecontroller to the monitor. If the power threshold is exceeded forfrequencies outside of the frequency pass band range set for the DSP,detection of this event is made by the monitor. The monitor thengenerates a signal, which is sent back to the controller. This signalmay be considered to be an alarm signal indicating impropertransmission. The controller can then initiate appropriate messaging viathe data network back to the terminal 90 or other appropriate ILECequipment to deal with the situation. If the ILEC has the capacity tocarry the upgraded service, station 90 can interact with the CLECthrough data communication to determine whether the upgraded service isto be authorized. For example, a user who has subscribed to POTS servicethrough the CLEC may install ADSL equipment or the like and attempt touse ADSL service without taking cognizance of the level of subscribedservice. The arrangement of FIG. 7 not only proactively blocks thisservice by filtering out the higher frequency signals but permits,through the monitoring feature, a renegotiated upgrade of the level ofservice. If the service is to be upgraded, station 90 transmits theappropriate information over the data network 84 to controller 82, whichthen selects the appropriate filter frequency pass band range to beprogrammed into DSP 80.

Relay 94 is controlled by controller 82 to be selectively actuated toconnect the unbundled leased subscriber loop 23 to the test unit toperform measurements of dc line parameters, such as voltage, resistanceand capacitance measurements. While mechanized loop testing iscommonplace, testing of unbundled leased lines has not heretofore beenreadily available to the ILEC. The test results are conveyed by the testunit to the controller, which can transmit test reports or test datathrough the data network 84 to the appropriate location in the CLECsystem.

In this disclosure there is shown and described only the preferredembodiments of the invention and but a few examples of its versatility.It is to be understood that the invention is capable of use in variousother combinations and environments and is capable of changes ormodifications within the scope of the inventive concept as expressedherein. For example, while the embodiments of FIGS. 6 and 7 are set inthe context of the CLEC switching office, the monitoring and testingfeatures can be installed at a remote site such as described for theembodiment of FIG. 5 without departing from the concepts of thisinvention.

What is claimed is:
 1. An apparatus for restricting communications overa subscriber loop circuit, leased from a local exchange carrier toanother carrier, to signals corresponding to a predetermined level ofloop service, said device a first connector for electrical connection tothe subscriber loop circuit; a second connector for electricalconnection to a communication circuit provided by the other carrier; anda variable bandpass filter connected between said first and secondconnectors for controlling a communication path between the subscriberloop circuit and the communication circuit provided by the othercarrier, wherein the filter is settable to a pass band that correspondsto the predetermined level of loop service.
 2. The apparatus of claim 1,wherein the variable bandpass filter is selectively settable to aplurality of pass bands, wherein each of the plurality of pass bandscorresponds to one of a plurality of possible levels of loop service. 3.The apparatus of claim 2, wherein: one of the pass bands of the variablebandpass filter corresponds to a first of the service levels and passesa limited frequency range for only telephone service; and another one ofthe pass bands of the variable bandpass filter corresponds to a secondof the service levels and passes a frequency range for enabling at leasta high speed data communication service.
 4. The apparatus of claim 3,wherein: the high speed data communication service is High bit rateDigital Subscriber Line (HDSL) service; and the passband correspondingto the HDSL service is a lowpass band ranging from a lower frequencylimit for the telephone service up to and including an upper limitassociated with the HDSL service.
 5. The apparatus of claim 3, wherein:the high speed data communication service is Asymmetric DigitalSubscriber Line (ADSL) service; and the passband corresponding to theADSL service is a lowpass band ranging from a lower frequency limit forthe telephone service up to and including an upper limit associated withthe ADSL service.
 6. The apparatus of claim 3, wherein: the high speeddata communication service is a data-only service; and the passbandcorresponding to the data-only service provides a notch filtercharacteristic for passing only signals in frequencies within afrequency range of the data-only service and for blocking signals infrequencies in a range otherwise associated with the telephone service.7. The apparatus of in claim 2, wherein: the variable bandpass filter isprogrammable, and the apparatus further comprises a controllerresponsive to externally supplied data for programming the filter to aselected one of the plurality of pass bands.
 8. The apparatus of claim7, wherein: said controller comprises an interface for connection to adata network linked to an external database in which informationidentifying a subscribed level of loop service for the subscriber loopcircuit is stored, and the externally supplied data comprisesidentifying information received from the database via the data network.9. The apparatus of claim 7, wherein said variable frequency bandpassfilter comprises a digital signal processor for attenuating signalshaving frequencies outside of the selected one of the plurality of passbands.
 10. The apparatus of claim 1, wherein each of the connectorscomprises a connector adapted for use on a portion of a distributionframe of a central office switching system.
 11. An apparatus for use bya local exchange carrier in a telephone network capable of selectivelyproviding telephone service as well as high speed data communicationservice, to restrict communications over a subscriber loop circuitleased from the local exchange carrier to another carrier, the apparatuscomprising: a first connector for electrical connection to thesubscriber loop circuit; a second connector for electrical connection toa communication circuit provided by the other carrier; a variablebandpass filter connected between said first and second convectors forcontrolling a communication path between the subscriber loop circuit andthe communication circuit provided by the other carrier; and acontroller responsive to externally supplied data for programming thefilter to pass a selected one of a plurality of pass bands correspondingto a subscribed level of service associated with the subscriber loopcircuit.
 12. The apparatus of claim 11, further comprising a monitor,connected in the communication path at a point between the variablebandpass filter and the second connector, for detecting powerdistribution throughout a wide frequency spectrum of signals transmittedin said path to or from the communication circuit provided by the othercarrier.
 13. The apparatus of claim 12, wherein the monitor is connectedto the controller; and in response to detection of a signal having apower level in excess of a predetermined threshold and a characteristicoutside the selected pass band, the monitor outputs a signal to thecontroller indicating an attempt to communicate at a service leveloutside the subscribed level of service associated with the subscriberloop circuit.
 14. The apparatus of claim 12, further comprising a testdevice connectable to the communication path at at least one side of thefilter, for measuring parameters of the subscriber loop circuit.
 15. Ina telephone network capable of selectively supplying telephone serviceand at least one high speed data communication service, a method ofrestricting communications over a subscriber loop circuit leased from alocal exchange carrier to another carrier to a selected service level,comprising the steps of: establishing a subscribed one of a plurality ofpossible service levels as the selected service level, for enablingcommunications for one or more of the services permissible over thesubscriber loop circuit; selectively setting a variable bandpass filterto one a plurality of pass bands, the one pass band corresponding to theestablished service level; and filtering communication signals passingbetween the subscriber loop circuit and a circuit of the other carrierthrough the variable bandpass filter, such that the one pass band limitsthe communication signals to a frequency range that corresponds to theselected service level.
 16. The method of claim 15, further comprisingthe steps of: monitoring communication signals sent from the othercarrier toward the subscriber loop circuit; and generating an alarmsignal in response to detection in said monitoring step of a signalhaving a power level in excess of a predetermined threshold at afrequency outside a frequency range of the selectively set pass band.17. The method of claim 16, further comprising the steps of: in responseto said alarm signal, determining whether the established service levelshould be changed to a new service level; and in response to a positivedetermination in the determining step, selectively setting the variablebandpass filter to a new one the plurality of pass bands, the new passband corresponding to the new service level; filtering subsequentcommunication signals passing between the subscriber loop circuit andthe circuit of the other carrier through the variable bandpass filter,such that the new pass band limits the communication signals to afrequency range that corresponds to the new service level.